package binary_tree;

import binary_tree.TreeNode;

public class LowestCommonAncestor {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if(root == null){
            return null;
        }
        if(root == p || root == q){
            return root;
        }
        TreeNode leftTree = lowestCommonAncestor(root.left,p,q);
        TreeNode rightTree = lowestCommonAncestor(root.right,p,q);
        if(leftTree != null && rightTree != null){
            return root;
        }else if(leftTree != null){
            return leftTree;
        }else{
            return rightTree;
        }
    }
}
